Music reproduction apparatus, audio player, and headphone

ABSTRACT

A music reproduction apparatus comprises an audio player and a headphone. The audio player comprises a circular main body, a display panel provided at a front face of the main body, an operating switch rotatably provided at a periphery of the display panel, and a wireless communication antenna provided at a rear face of the main body. The headphone comprises a circular main body, a speaker provided at one face of the main body, a wireless communication antenna provided at the other face of the main body, and an ear hook provided at the outside of the main body.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a music reproduction apparatusthat wirelessly connects a portable audio player and a headphone, andthe audio player and headphone.

[0003] 2. Description of the Related Art Conventionally, in the portableaudio player, the audio player and the headphone are connected to eachother via a connection cord. This cord gets in the way of a user, andmakes it difficult to use the audio player while enjoying sport such aswhen one goes jogging while listening to music, for example. Aconnection cord is required to connect such an audio player to anotherdevice, and degradation of sound quality occurs. If it is aimed to usethe headphone for another purpose, the audio player cannot be usedunless the cord has been connected again. Further, it is difficult tolisten to the same music by a plurality of people while connecting aplurality of headphones to one audio player. It is necessary to providea plurality of jacks at the audio player, and a structural restrictionoccurs.

[0004] Because of this, in recent portable audio players, a wirelesstype audio player is employed such that voice information isfrequency-modulated in an analog manner, and the modulated informationis delivered to the headphone wirelessly by using radio or infraredrays.

[0005] However, a conventional wireless portable audio player transmitsvoice information in an analog manner, and has a problem that soundquality is degraded. A conventional wireless portable audio player usinginfrared rays cannot connect a plurality of headphones because of itsstrong directivity. In addition, a conventional wireless portable audioplayer using frequency-modulation is not configured to connect aplurality of headphones yet. Further, in the conventional wireless typeaudio player, a combination of the audio player and headphone capable ofmaking wireless communication is predetermined. It is not possible tofreely connect the headphone to the audio player.

BRIEF SUMMARY OF THE INVENTION

[0006] It is an object of the present invention to provide a musicreproduction apparatus which is free of sound quality degradation, andin which a plurality of people can listen to the same music by using aplurality of headphones.

[0007] It is another object of the present invention to provide an audioplayer and a headphone usable for other purposes, as well for use in awireless connection.

[0008] According to one aspect of the present invention, there isprovided an audio player comprising a circular main body, a displaypanel provided at one face of the main body, an operating switchrotatably provided at a periphery of the display panel, and a wirelesscommunication antenna provided at the other face of the main body.

[0009] According to another aspect of the present invention, there isprovided a headphone comprising a circular main body, a speaker providedon one face of the main body, a wireless communication antenna providedat the other face of the main body, and an ear hook provided at the mainbody.

[0010] According to another aspect of the present invention, there isprovided a music reproduction apparatus comprising an audio player and aheadphone connected to the audio player via a wireless digital datatransmission channel, the audio player comprising a transmitterconfigured to transmit music data with an error correction code to theheadphone, a reproduction request detector configured to detect areproduction request from the headphone, and a retransmission sectionconfigured to re-transmit requested music data to the headphone based onthe reproduction request detected by the reproduction request detector,and the headphone comprising a receiver configured to receive music datatransmitted from the audio player, an error detecting/correcting sectionconfigured to detect and correct an error of the music data received bythe receiver and determine whether or not data retransmission isrequired, and a retransmission request section configured to, when theerror detecting/correcting means determines that data retransmission isrequired, transmit a retransmission request to the audio player.

[0011] According to another aspect of the present invention, there isprovided a music reproduction apparatus comprising an audio player and apair of left and right headphones connected to the audio player via awireless digital data transmission channel, the audio player comprisinga transmitter configured to transmit left and right music data to theleft and right headphones, and each of the left and right headphonescomprising a receiver configured to receive the left and right musicdata transmitted from the audio player, and a data extracting sectionconfigured to extract one of the left and right music data received bythe receiver.

[0012] According to another aspect of the present invention, there isprovided a music reproduction apparatus comprising an audio player and apair of left and right headphones connected to the audio player via awireless digital data transmission channel, the audio player comprisinga transmitter configured to transmit left and right music data to theleft and right headphones respectively.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0013] The accompanying drawings, which are incorporated in andconstitute a part of the specification, illustrate embodiments of thepresent invention and, together with the general description given aboveand the detailed description of the embodiments given below, serve toexplain the principles of the present invention in which:

[0014]FIGS. 1A, 1B, 1C and 1D are views each showing an externalconfiguration of an audio player according to a first embodiment of thepresent invention;

[0015]FIGS. 2A, 2B and 2C are views showing an external configuration ofa headphone in the first embodiment;

[0016]FIGS. 3A and 3B are views each showing an external configurationwhen a microphone is stored in a headphone;

[0017]FIG. 4 is a block diagram showing a circuit configuration of theaudio player and a headphone according to the first embodiment of thepresent invention;

[0018]FIG. 5 is a block diagram showing a circuit configuration of anaudio player and a pair of headphones according to a second embodimentof the present invention;

[0019]FIG. 6 is a block diagram showing a circuit configuration of anaudio player and a pair of headphones according to a third embodiment ofthe present invention;

[0020]FIG. 7 is a block diagram showing a circuit configuration of amicrophone section provided at a headphone according to a fourthembodiment of the present invention;

[0021]FIG. 8 is a block diagram showing a circuit configuration of anoperating switch section of a headphone and a control section of anaudio player according to a fifth embodiment of the present invention;

[0022]FIG. 9 is a block diagram showing a circuit configuration of amicrophone section of a headphone and a control section of an audioplayer according to a sixth embodiment of the present invention;

[0023]FIG. 10 is a block diagram showing a circuit configuration of anaudio player and a headphone according to a seventh embodiment of thepresent invention; and

[0024]FIG. 11 is a block diagram showing a circuit configuration of aheadphone according to an eighth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0025] An embodiment of a music reproduction apparatus, an audio player,and a headphone according to the present invention will now be describedwith reference to the accompanying drawings.

[0026] First Embodiment

[0027]FIG. 1A to FIG. 1D are views each showing an externalconfiguration of an audio player 10 according to the first embodiment ofthe present invention. FIG. 1A is a front view, FIG. 1B is a side view,FIG. 1C is a rear view, and FIG. 1D is a bottom view. FIG. 2A to FIG. 2Care external configurations of a right headphone 20. FIG. 2A is a leftside view, FIG. 2B is a front view, and FIG. 2C is a right side view.

[0028] In the audio player 10 shown in FIG. 1A to FIG. 1D, an LCDdisplay panel 12, for example, formed in a circular shape is provided atthe front face side of a circular case main body 11, and a ring shapedaudio operation switch 13 is rotatably provided at the outer peripherythereof. The audio operating switch 13 comprises a rotary switch, andcan make operations for FF (fast feed), REW (rewinding), PLAY(playback), and STOP (stop), for example by rotating the switch. Volumecontrol switches 15 a and 15 b are provided at the outside of the casemain body 11. The switch 15 a is a push button type switch forincreasing a volume, and the switch 15 b is a push button type switchfor decreasing a volume.

[0029] A wireless communication antenna 14 for transmitting/receiving anelectric wave is rotatably provided at the rear face side of the casemain body 11, as shown in FIG. 1C. The antenna 14 comprises a rotaryswitch for turning ON/OFF transmission and reception of electronicwaves. The rotary switch can be compatible with a power switch of theaudio player.

[0030] A card slot 16 is provided at the lower side of the case mainbody 11, as shown in FIG. 1D. A small sized memory card or the like ismounted to the card slot 16. As a memory card, for example, a compactflash, a smart medium, or an SD (Secure digital) memory card may beused.

[0031] The audio player 10 reproduces music stored in the memory card,and transmits the reproduced digital music data to the headphone 20 viawireless communication. Bluetooth, for example, is used for wirelesscommunication. Bluetooth is a specification for short distance wirelesscommunication in which wireless communication within 10 m is generallycarried out by using an ISM (Industry Science Medical) band of 2.4 GHzbandwidth. Bluetooth uses a frequency hopping system as a spreadspectrum technique, and a maximum of eight devices can be connected bytime division multiple system.

[0032] In the right headphone 20 shown in FIG. 2A to FIG. 2C, an antenna23 is provided on one face of a circular case main body 21, and a ringshaped ON/OFF switch 22 is provided at the outer periphery thereof. TheON/OFF switch 22 comprises a rotary switch, and turns ON/OFF the powerby rotationally operating the switch. A speaker 24 is provided on theother face of the case main body 21. An ear hook 25 is provided at theoutside of the case main body 21. The ear hook 25 or case main body 21incorporates a battery. The headphone 20 is connected to the audioplayer 10 via wireless communication, receives digital music datadelivered from the audio player 10, converts the received data into ananalog signal, and drives the speaker 24.

[0033] Although FIG. 2A to FIG. 2C show the right headphone 20, a leftheadphone is configured in the same manner.

[0034]FIG. 3A and FIG. 3B each show an exemplary configuration when amicrophone 28 is provided at the headphone 20, and are views seen fromthe speaker 24 side. FIG. 3A shows a state when the microphone 28 isstored, and FIG. 3B shows a state when the microphone 28 is pulled out.

[0035] In the headphone 20, a microphone section 27 is provided at theouter periphery of the speaker 24. The microphone section 27 rotatablymaintains one end of a semi-circular ring shaped microphone storage arm,and stores the microphone 28 at its tip end. At the outer periphery ofthe speaker 24, a semi-circular ring shaped member similar to themicrophone section 27 is disposed at a position opposite to themicrophone section 27, thereby maintaining aesthetic appeal. Theheadphone 20 comprises a switch for detecting a position of themicrophone section 27. When the microphone 28 is pulled out, the pulledout microphone 28 is detected by the switch, and can be used as anearphone microphone. In general, the headphone 20 is used while themicrophone 28 is stored as shown in FIG. 3A.

[0036] An electronic circuit of the audio player 10 and headphone 20will be described with reference to FIG. 4. The audio player 10comprises a music file 31 which stores music data read out from a memorycard; a digital transmission data generator 32 which generates digitaltransmission data from the music file 31; and a digital data modulatingdevice 33 which modulates digital data, thereby transmitting themodulated data to the headphone 20 wirelessly. The audio player 10further comprises a receiving device 34 which receives a retransmissionrequest command delivered from the headphone 20; and a retransmissionrequest interpreter 35 which interprets the retransmission requestcommand received by the receiving device 34, thereby inputting theinterpreted command to the digital transmission data generator 32.

[0037] The headphone 20 comprises a receiving device 41 which receivesdata delivered from the audio player 10; an error detecting/correctingcircuit 42 which detects and corrects an error of the received signal; adata buffer 43 which stores the error corrected data; and a D/Aconverting/amplifying circuit 44 which converts and amplifies thedigital data stored in the data buffer 43 sequentially into analogsignals, thereby driving the speaker 24. The headphone 20 furthercomprises a retransmission request generator 45 which, in the case wherean error cannot be corrected by the error detecting/correcting circuit42 or in the case where some of the data cannot be received because theelectric waves are interrupted, generates a retransmission request; anda digital data modulating device 46 which modulates the generatedretransmission request, thereby transmits the request to the audioplayer 10.

[0038] In the above configuration, the audio player 10 generates digitaltransmission data based on the music file 31 at the digital transmissiondata generator 32, and modulates the generated data by the digital datamodulating device 33, thereby wirelessly transmitting the modulated datato the headphone 20. An error correction code is added to datatransmitted from the audio player 10.

[0039] The headphone 20 receives music data delivered from the audioplayer 10 by the receiving device 41, carries out error detection anderror correction by the error detecting/correcting circuit 42, andstores the resultant data in the data buffer 43. The data stored in thedata buffer 43 are sequentially read out to the D/A amplifying circuit44, the read out data is converted into an analog signal, and isamplified, thereby driving the speaker 24.

[0040] In the case where an error cannot be corrected by the errordetecting/correcting circuit 42 or in the case where some of the datacannot be received because the electric waves are interrupted, a commandfor generating a retransmission request is delivered from the errordetecting/correcting circuit 42 to the retransmission request generator45, and a retransmission request command is outputted from theretransmission request generator 45. The retransmission request commandis modulated by the digital data modulating device 46, and the modulatedcommand is delivered to the audio player 10.

[0041] The audio player 10 receives a retransmission request commanddelivered from the headphone 20 by the receiving device 34, interpretsthe received command by the retransmission request interrupting section35, and instructs the digital transmission data generator 32 toretransmit data. The digital transmission data generator 32 retransmitsdata on a portion requested in accordance with the instruction from theretransmission request interpreter 35.

[0042] As has been described above, according to the first embodiment,the audio player 10 and headphone 20 are connected to each other viawireless communication, thus eliminating a connection cord, and freeingthe user of cord problems. Because of this, the user can jog whilelistening to music. In the case of storing the audio player 10 andheadphone 20 as well, the cord does not interrupt the user.

[0043] Digital music data is transmitted from the audio player 10 to theheadphone 20, and thus, a high quality sound can be maintained withoutdegrading a sound quality. The error detecting/correcting circuit 42 isprovided at the headphone 20, thereby carrying out error detection anderror correction. In addition, in the case where an error cannot becorrected by the error detecting/correcting circuit 42 or in the casewhere part of data cannot be received because electric waves areinterrupted, a retransmission request is generated, thereby data on aportion requested from the audio player 10 is retransmitted. Thus, musicdata can be transferred without interruption or degradation. That is,the data corrected by the error detecting/correcting circuit 42 orretransmitted data is temporarily stored in the data buffer 43, andthen, the temporarily stored data is read out sequentially by the D/Aconverting/amplifying circuit 44. Thus, even in the case data has beenretransmitted, the data can be outputted to the speaker 24 withoutinterruption.

[0044] Digital music data is transmitted wirelessly from the audioplayer 10 so that a plurality of people can listen to the same music byusing a plurality of headphones 20. For example, in the case whereBluetooth is used as a wireless communication system, a maximum of eightpersons can listen to the same music.

[0045] A wireless connection between the audio player 10 and theheadphone 20 is provided, thereby providing a higher degree of freedomin the design and configuration of the audio player 10 and the headphone20.

[0046] Other embodiments of the audio player according to the presentinvention will be described. The same portions as those of the firstembodiment will be indicated in the same reference numerals and theirdetailed description will be omitted. That is, an external configurationof the audio player and headphone is identical to that of the firstembodiment. Embodiments which are different in circuit configurationwill be described below.

[0047] Second Embodiment

[0048]FIG. 5 shows a circuit configuration of an audio player 10 and apair of headphones 20 according to the second embodiment of the presentinvention.

[0049] The audio player 10 generates stereo music data produced when L(left) and R (right) channels are mixed at the digital transmission datagenerator 32 to be outputted to the digital data modulating device 33.The digital data modulating device 33 modulates L and R mixed musicdata, and transmits the modulated data to an L-side headphone 20 a andan R-side headphone 20 b.

[0050] The L-side head phone 20 a comprises a receiving device 51 a,L-side data extracting section 52 a, D/A converting/amplifying circuit53 a, and L-side speaker 24 a. The L and R mixed music data received bythe receiving device 51 a is inputted to the L-side data extractingsection 52 a, and only the L-side data is extracted. Then, the L-sidedata is converted into an analog signal by the D/A converting/amplifyingcircuit 53 a, and the converted signal is amplified, thereby driving theL-side speaker 24 a.

[0051] Similarly, the R-side headphone 20 b comprises a receiving device51 b, R-side data extracting section 52 b, D/A converting/amplifyingcircuit 53 b, and R-side speaker 24 b. The L and R mixed music datareceived by the receiving device 51 b is inputted to the R-side dataextracting section 52 b, and only the R-side data is extracted. Then,the R-side data is converted into an analog signal by the D/Aconverting/amplifying circuit 53 b, and the converted signal isamplified, thereby driving the R-side speaker 24 b.

[0052] The L-side data extracting section 52 a and the R-side dataextracting section 52 b extract signals of L and R based on a codeincluded in received data or extract the signals of L and R based on atime division system.

[0053] With the above configuration, the signals of L and R can bereliably separated at the headphones 20 a and 20 b, and the user canlisten to stereo music.

[0054] Third Embodiment

[0055]FIG. 6 shows a circuit configuration of the audio player 10 andthe pair of headphones 20 according to the third embodiment of thepresent invention.

[0056] In the third embodiment, at the audio player 10, an L-R separator36 is provided following to the digital transmission data generator 32,and signals of L and R are separated from the data outputted from thedigital transmission data generator 32. The signal of L separated by theL-R separator 36 is inputted to a digital data modulating device 33a,and the signal of R is inputted to a digital data modulating device 33b. The digital data modulating devices 33 a and 33 b modulate signalsseparated by the L-R separator 36, and transmit the separated signals tothe L-side headphone 20 a and the R-side headphone 20 b. The digitaldata modulating devices 33 a and 33 b transmit signals by using afrequency division system, for example.

[0057] The L-side headphone 20 a comprises a receiving device 51 a, aD/A converting/amplifying circuit 53 a, and an L-side speaker 24 a. Thereceiving device 51 a selectively receives an L-side signal transmittedfrom the digital data modulating device 33 a, and inputs the receivedsignal to the D/A converting/amplifying circuit 53 a. The D/Aconverting/amplifying circuit 53 a converts the L-side signal receivedby the receiving device 51 a into an analog signal, and amplifies theconverted signal, thereby driving the L-side speaker 24 a.

[0058] The R-side headphone 20 b comprises a receiving device 51 b, aD/A converting/amplifying circuit 53 b, and an R-side speaker 24 b. Thereceiving device 51 b selectively receives an R-side signal transmittedfrom the digital data modulating device 33 b, and inputs the receivedsignal to the D/A converting/amplifying circuit 53 b. The D/Aconverting/amplifying circuit 53 b converts an R-side signal received bythe receiving device 51 b into an analog signal, and amplifies theconverted signal, thereby driving the R-side speaker 24 b.

[0059] In the third embodiment, the signals of L and R are separated atthe audio player 10, and the separated signals are modulated andtransmitted independently by digital data modulating devices 33 a and 33b, respectively. Therefore, the pair of headphones 20 a and 20 breceives the signals of L and R separated in advance, the signals beingtransmitted from the audio player 10, and the user can listen to stereomusic.

[0060] Fourth Embodiment

[0061] The fourth embodiment of the present invention will be describedwith reference to FIG. 7.

[0062] The fourth embodiment relates to a circuit configuration when themicrophone 28 is stored in the headphone 20 as shown in FIG. 3A and FIG.3B. As shown in FIG. 7, the microphone section 27 comprises themicrophone 28, an A/D converting device 61, and digital data modulatingdevice 62, and is configured so as to turn ON/OFF a power supply of themicrophone section 27 by a detection signal from a microphone positiondetector 63.

[0063] The microphone position detector 63 outputs a power OFF signalwhile the microphone 28 is stored in the headphone 20 as shown in FIG.3A, and outputs a power ON signal while the microphone 28 is pulled outas shown in FIG. 3B. Therefore, when the microphone 28 is pulled outfrom the headphone 20, the power ON signal is outputted from themicrophone position detector 63, and the microphone section 27 operates.In this state, when a voice is inputted from the microphone 28, thevoice signal is converted from an analog into a digital signal by theA/C converting device 61, the converted signal is modulated by thedigital data modulating device 62, and the modulated data is transmittedto the audio player 10.

[0064] In the manner described above, the user's voice data can betransmitted from the headphone 20 to the audio player 10.

[0065] Although FIG. 7 describes a case where the digital datamodulating device 62 transmits voice data to the audio player 10, thedigital data modulating device 62 is connectable to a device other thanthe audio player 10 or a device having an I/F of the same electric wavesas the audio player 10 such a portable telephone/PHS, a personalcomputer, a television and the like. Therefore, the headphone 20 can beused in a method described below.

[0066] For example, when the headphone 20 is used by being wirelesslyconnected to the audio player 10, in the case where a portabletelephone, PHS, or a home telephone (hereinafter, referred to as aportable telephone) is called, the fact that the portable telephone iscalled is transmitted by electric waves to the audio player 10 and theheadphone 20. The audio player 10 temporarily stops reproductionautomatically or reduces the volume, and the headphone 20 outputs fromthe speaker 24 a sound indicating that the portable telephone is called.At this time, the user pulls out the microphone 28 stored in theheadphone 20, thereby starting operation as an earphone microphone ofthe portable telephone. When the portable telephone detects that theheadphone 20 starts operation as an earphone microphone of the portabletelephone, the current state goes from a called state to a talk state.When the audio player 10 detects that the headphone 20 starts asoperation as an earphone microphone, reproduction is temporarilystopped.

[0067] Then, after the conversation is over, when the microphone 28 ofthe headphone 20 is stored, the headphone 20 restarts operation as ageneral headphone. When the portable telephone detects that an operationas a headphone is restarted, the telephone cuts out talking. When theaudio player 10 detects that an operation as a headphone is restarted,the audio player restarts music reproduction that has been temporarilystopped.

[0068] As has been described above, talk processing can be carried outfor a portable telephone by the microphone 28 of the headphone 20.

[0069] Otherwise, for example, while a portable telephone is waiting fora call, when it is detected that the headphone 20 starts operation as anearphone microphone, the portable telephone can execute processing thatvocally recognizes voice data of the microphone 28 delivered from theheadphone 20, and dials the counterpart.

[0070] Fifth Embodiment

[0071] The fifth embodiment of the present invention will be describedwith reference to FIG. 8.

[0072] The fifth embodiment relates to a circuit configuration when theheadphone 20 is operated as a remote controller of the audio player 10.

[0073] As shown in FIG. 8, an operating switch section 70 which operatesthe audio player 10 is provided at the headphone 20. The operatingswitch section 70 comprises operating switches 71 such as FF (fastfeed), REW (rewinding), PLAY (playback), STOP (stop), volume control andthe like for operating the audio player 10; a switch state detector 72which detects a state of the operating switches 71; a digital datamodulating device 73 which modulates and delivers a command relevant toa switch detected by the switch state detector 72.

[0074] The audio player 10 receives an electric wave transmitted fromthe operating switch section 70 of the headphone 20 by a control section80, and executes a control operation corresponding to the receivedsignal. The control section 80 comprises a receiving device 81 whichreceives an electric wave transmitted from the digital data modulatingdevice 73 of the operating switch section 70; a command interpreter 82which interprets a command corresponding to the received signal by thereceiving device 81, i.e., a command corresponding to the operatingswitch 71; and a player operation control section 83 which controlsplayer operation in accordance with the interpreted command. The playeroperation control section 83 generally controls a player operationaccording to an operation of a player side operating switch 84.

[0075] In the above configuration, the operating switch 71 such as PLAY(playback), STOP (stop) or the like, for example, is operated at theheadphone 20 side, and such a switching operation is detected by theswitch state detector 72, and the command corresponding to the operatingswitch is delivered to the digital data modulating device 73. Thedigital data modulating device 73 modulates a command outputted from theswitch state detector 72, and transmits the modulated command to theaudio player 10. The audio player 10 receives the electric wavestransmitted from the digital data modulating device 73 by the receivingdevice 81, interprets the content of the command by the commandinterpreter 82, and inputs the interpreted content to the playeroperation control section 83. The player operation control section 83controls player operations such as PLAY (playback), STOP (stop) or thelike in accordance with the command interpreted by the commandinterpreter 82.

[0076] As has been described above, the operating switch section 70 isprovided at the headphone 20, whereby the headphone 20 can be operatedas a remote controller of the audio player 10.

[0077] Sixth Embodiment

[0078] The sixth embodiment relates to a circuit configuration when theheadphone 20 is operated as a remote controller of the audio player 10by using the microphone 28 of the headphone 20 and a voice recognitiontechnique.

[0079] As shown in FIG. 9, the microphone section 27 shown in FIG. 7 isprovided at the headphone 20. The microphone section 27 comprises themicrophone 28, A/D converting device 61, and digital data modulatingdevice 62.

[0080] The audio player 10 comprises a control section 80A similar tothe control section 80 according to the fifth embodiment. The controlsection 80A comprises a voice command interpreter 85 provided instead ofthe command interpreter 82 in the control section 80.

[0081] In the case where the headphone 20 is operated as a remotecontroller, the microphone 28 is pulled out from the headphone 20, andthe microphone vocally generates a predetermined operating command suchas “reproduction” or “next music”, for example, to the audio player 10.The voice data inputted to the microphone 28 is converted into digitaldata by the A/D converting device 61, and the converted data istransmitted to the control section 80A of the audio player 10 modulatedby the digital data modulating device 62. The control section 80Areceives the voice data delivered from the head phone 20 by thereceiving device 81, interprets the received data by the voice commandinterpreter 82, and supplies the interrupted data to the playeroperation control section 83. The player operation control section 83controls a player operation in accordance with the content interpretedby the voice command interpreter 82.

[0082] As has been described above, the microphone section 27 isprovided at the headphone 20, and the voice command interpreter 82 isprovided at the control section 80A of the audio player 10, whereby avoice command is assigned from the microphone 28 of the headphone 20,making it possible to operate the audio player 10.

[0083] Seventh Embodiment

[0084] The seventh embodiment of the present invention will be describedwith reference to FIG. 10.

[0085] The seventh embodiment relates to a circuit configuration wheninformation on the battery level of the audio player 10 and theheadphone 20 is exchanged, a no-battery warning sound or warning messageis generated, and a battery level is displayed on the display panel 12of the audio player 10.

[0086] As shown in FIG. 10, a battery level detector 92 which detectsthe level of a battery 91 is provided at the audio player 10.Information on the battery residue detected by the battery leveldetector 92 is delivered to a display device control section 93 to bedisplayed on the display panel 12. If the residue of the battery 91 isbelow a predetermined value, the battery level detector 92 detects suchstate, and outputs a warning sound generating command to a warning soundgenerator 94. The warning sound generator 94 generates a warning soundor a warning message in accordance with a command from the battery leveldetector 92, modulates the sound or message by the digital datamodulating device 33, and transmits it to the headphone 20.

[0087] The headphone 20 receives the warning sound or warning messagetransmitted from the audio player 10 by the receiving device 51, andconverts the sound or message into an analog signal by the D/Aconverting/ amplifying circuit 53, thereby driving the speaker 24. Theheadphone 20 detects the residue of an incorporated battery 55 by abattery level detector 56, and outputs a warning sound generatingcommand to a warning sound generator 57 when the battery residue isbelow a predetermined value. The warning sound generator 57 generates awarning sound in accordance with a command from the battery leveldetector 56, and outputs the generated sound from the speaker 24 via theD/A converting/amplifying circuit 53.

[0088] The residue information on the battery 55 detected by the batterylevel detector 56 is modulated by the digital data modulating device 46,and the modulated information is transmitted to the audio player 10. Theaudio player 10 receives the battery residue information delivered fromthe headphone 20 by the receiving device 34, outputs the receivedinformation to a display device control section 93, and displays theoutputted information on the display panel 12.

[0089] With the above configuration, information on the battery level ofthe audio player 10 and the headphone 20 is exchanged, a no-batterywarning sound or a warning message is generated, and the battery residuecan be displayed on the display panel 12 of the audio player 10.

[0090] Eighth Embodiment

[0091] The eighth embodiment of the present invention will be describedwith reference to FIG. 11.

[0092] The eighth embodiment relates to a circuit configuration when theheadphone 20 approximately measures a distance to the audio player 10 byusing electric waves, and a warning sound is outputted from the speaker24 when the distance exceeds a predetermined distance.

[0093] As shown in FIG. 11, the headphone 20 comprises an electric fieldintensity measuring section 58 and an error rate measuring section 59,receives transmission electric waves from the audio player 10 by thereceiving device 51, and inputs the received signal to the electricfield intensity measuring section 58 and error rate measuring section59. The electric field intensity measuring section 58 measures anelectric field intensity from a level of the received signal, estimatesa distance to the audio player 10 from its electric field intensity, andoutputs a warning sound generating command to the warning soundgenerator 57 when the estimated distance exceeds a predetermineddistance or the detected electric field intensity is lower than apredetermined value.

[0094] The error rate measuring section 59 measures an error rate ofreceived information based on an error detection code included in thetransmitted information from the audio player 10, estimates a distancewith the audio player 10 from the result, and outputs a warning soundgenerating command to the warning sound generator 57 when the estimateddistance exceeds a predetermined distance or the detected error rate ishigher than a predetermined value.

[0095] The warning sound generator 57 generates a warning sound in thecase where a warning sound generating command is generated from theelectric field intensity measuring section or error rate measuringsection 59, and outputs the warning from the speaker 24 via the D/Aconverting/amplifying circuit 53.

[0096] As described above, the electric field intensity measuringsection 58 and the error rate measuring section 59 are provided at theheadphone 20, and a distance to the audio player 10 is measured, wherebya warning sound can be outputted from the speaker 24 in the case wherethe distance with the audio player 10 exceeds a predetermined distance.Therefore, for example, in the case where an attempt to move while theaudio player 10 is set down somewhere, a warning sound sounds. As aresult, the mislaying of the audio player 10 can be prevented.Similarly, the theft of the audio player 10 can be effectivelyprevented.

[0097] Although the above described embodiments show a case where theaudio player 10 is connected to the headphone 20, the audio player canbe connected to another device by using electric waves as well as theheadphone 20. For example, connection is made to another audio player orpersonal computer having an I/F of the same electric waves as the audioplayer 10, and a music file owned by each of these elements can betransmitted/received. The audio player 10 is connected to a portabletelephone having an I/F of the same electric waves as the audio player10, thereby making it possible to download a music file over theInternet via this portable telephone.

[0098] As has been described above in detail, according to aspects ofthe present invention, digital music data is transmitted from the audioplayer to the headphone, and thus, a high quality sound can bemaintained. The error detecting/correcting circuit is provided at theheadphone, thereby carrying out error correction. In the case whereerror correction cannot be carried out or in the case where some of thedata cannot be received because electric waves are interrupted, data isretransmitted, thus making it possible to reliably prevent interruptionor degradation of the music data. Further, digital music data istransmitted wirelessly from the audio player, and a plurality of peoplecan listen to the same music by using a plurality of headphones. Each ofthe audio player and the headphone comprise a transmitting/receivingdevice, thus making it possible to facilitate the audio player orheadphone operating as an electronic device having another purpose aswell as music data transmission/receiving.

[0099] Additional advantages and modifications will readily occur tothose skilled in the art. Therefore, the present invention in itsbroader aspects is not limited to the specific details, representativedevices, and illustrated examples shown and described herein.Accordingly, various modifications may be made without departing fromthe spirit or scope of the general inventive concept as defined by theappended claims and their equivalents.

What is claimed is:
 1. An audio player comprising: a circular main body;a display panel provided at one face of said main body; an operatingswitch rotatably provided at a periphery of said display panel; and awireless communication antenna provided at the other face of said mainbody.
 2. The audio player according to claim 1, further comprising acard slot provided at a side face of said main body.
 3. A headphonecomprising: a circular main body; a speaker provided on one face of saidmain body; a wireless communication antenna provided at the other faceof said main body; and an ear hook provided at said main body.
 4. Theheadphone according to claim 3, further comprising a rotary power switchrotatably provided at a periphery of said antenna.
 5. A musicreproduction apparatus comprising an audio player and a headphoneconnected to said audio player via a wireless digital data transmissionchannel, said audio player comprising: a transmitter configured totransmit music data with an error correction code to said headphone; areproduction request detector configured to detect a reproductionrequest from said headphone; and a retransmission section configured tore-transmit requested music data to said headphone based on thereproduction request detected by said reproduction request detector, andsaid headphone comprising: a receiver configured to receive music datatransmitted from said audio player; an error detecting/correctingsection configured to detect and correct an error of the music datareceived by said receiver and determine whether or not dataretransmission is required; and a retransmission request sectionconfigured to, when said error detecting/correcting means determinesthat data retransmission is required, transmit a retransmission requestto said audio player.
 6. The music reproduction apparatus according toclaim 5, wherein said headphone comprises an operating switch andwirelessly transmits an operating state signal of said operating switchto said audio player, and said audio player controls a player operationbased on the operating state signal.
 7. The music reproduction apparatusaccording to claim 5, wherein said headphone comprises a microphone andwirelessly transmits a voice signal input from the microphone andindicating a command to said audio player, and said audio player carriesout voice recognition and command interpretation for the voice signaltransmitted from said headphone and controls a player operation based ona result of the command interpretation.
 8. The music reproductionapparatus according to claim 5, wherein said audio player comprises aninterface capable of wirelessly connecting a plurality of headphones. 9.The music reproduction apparatus according to claim 5, wherein saidaudio player comprises a first battery level detector configured todetect a level of an incorporated battery of the audio player, and saidheadphone comprises a second battery level detector configured to detecta level of an incorporated battery of the headphone and a first warningsection configured to issue a warning sound when the level of theincorporated battery detected by at least one of said first batterylevel detector and said second battery level detector is lower than apredetermined value, and said audio player comprises a second warningsection configured to display a warning message when the level of theincorporated battery detected by at least one of said first batterylevel detector and said second battery level detector is lower than thepredetermined value.
 10. The music reproduction apparatus according toclaim 5, wherein said headphone comprises an electric field intensitydetector configured to detect an electric field intensity of an electricwave transmitted from said audio player and a warning section configuredto issue warning when the detected electric field intensity is lowerthan a predetermined value.
 11. The music reproduction apparatusaccording to claim 5, wherein said headphone comprises an error ratedetector configured to detect an error rate of an electric wavetransmitted from said audio player and a warning section configured toissue warning when the detected error rate is higher than apredetermined value.
 12. The music reproduction apparatus according toclaim 5, wherein said headphone comprises an electric field intensitydetector configured to detect an electric field intensity of an electricwave transmitted from said audio player, a first distance estimatorconfigured to estimate a first distance between said headphone and saidaudio player, an error rate detector configured to detect an error rateof the electric wave transmitted from said audio player, a seconddistance estimator configured to estimate a second distance between saidheadphone and said audio player, and a warning section configured toissue warning when at least one of the estimated first distance and theestimated second distance is longer than a predetermined distance.
 13. Amusic reproduction apparatus comprising an audio player and a pair ofleft and right headphones connected to said audio player via a wirelessdigital data transmission channel, said audio player comprising: atransmitter configured to transmit left and right music data to the leftand right headphones, and each of said left and right headphonescomprising: a receiver configured to receive the left and right musicdata transmitted from said audio player; and a data extracting sectionconfigured to extract one of the left and right music data received bysaid receiver.
 14. The music reproduction apparatus according to claim13, wherein said headphone comprises an operating switch and wirelesslytransmits an operating state signal of said operating switch to saidaudio player, and said audio player controls a player operation based onthe operating state signal.
 15. The music reproduction apparatusaccording to claim 13, wherein said headphone comprises a microphone andwirelessly transmits a voice signal input from the microphone andindicating a command to said audio player, and said audio player carriesout voice recognition and command interpretation for the voice signaltransmitted from said headphone and controls a player operation based ona result of the command interpretation.
 16. The music reproductionapparatus according to claim 13, wherein said audio player comprises aninterface capable of wirelessly connecting a plurality of headphones.17. The music reproduction apparatus according to claim 13, wherein saidaudio player comprises a first battery level detector configured todetect a level of an incorporated battery of the audio player, and saidheadphone comprises a second battery level detector configured to detecta level of an incorporated battery of the headphone and a first warningsection configured to issue a warning sound when the level of theincorporated battery detected by at least one of said first batterylevel detector and said second battery level detector is lower than apredetermined value, and said audio player comprises a second warningsection configured to display a warning message when the level of theincorporated battery detected by at least one of said first batterylevel detector and said second battery level detector is lower than thepredetermined value.
 18. The music reproduction apparatus according toclaim 13, wherein said headphone comprises an electric field intensitydetector configured to detect an electric field intensity of an electricwave transmitted from said audio player and a warning section configuredto issue warning when the detected electric field intensity is lowerthan a predetermined value.
 19. The music reproduction apparatusaccording to claim 13, wherein said headphone comprises an error ratedetector configured to detect an error rate of an electric wavetransmitted from said audio player and a warning section configured toissue warning when the detected error rate is higher than apredetermined value.
 20. The music reproduction apparatus according toclaim 13, wherein said headphone comprises an electric field intensitydetector configured to detect an electric field intensity of an electricwave transmitted from said audio player, a first distance estimatorconfigured to estimate a first distance between said headphone and saidaudio player, an error rate detector configured to detect an error rateof the electric wave transmitted from said audio player, a seconddistance estimator configured to estimate a second distance between saidheadphone and said audio player, and a warning section configured toissue warning when at least one of the estimated first distance and theestimated second distance is longer than a predetermined distance.
 21. Amusic reproduction apparatus comprising an audio player and a pair ofleft and right headphones connected to said audio player via a wirelessdigital data transmission channel, said audio player comprising atransmitter configured to transmit left and right music data to the leftand right headphones respectively.
 22. The music reproduction apparatusaccording to claim 21, wherein said headphone comprises an operatingswitch and wirelessly transmits an operating state signal of saidoperating switch to said audio player, and said audio player controls aplayer operation based on the operating state signal.
 23. The musicreproduction apparatus according to claim 21, wherein said headphonecomprises a microphone and wirelessly transmits a voice signal inputfrom the microphone and indicating a command to said audio player, andsaid audio player carries out voice recognition and commandinterpretation for the voice signal transmitted from said headphone andcontrols a player operation based on a result of the commandinterpretation.
 24. The music reproduction apparatus according to claim21, wherein said audio player comprises an interface capable ofwirelessly connecting a plurality of headphones.
 25. The musicreproduction apparatus according to claim 21, wherein said audio playercomprises a first battery level detector configured to detect a level ofan incorporated battery of the audio player, and said headphonecomprises a second battery level detector configured to detect a levelof an incorporated battery of the headphone and a first warning sectionconfigured to issue a warning sound when the level of the incorporatedbattery detected by at least one of said first battery level detectorand said second battery level detector is lower than a predeterminedvalue, and said audio player comprises a second warning sectionconfigured to display a warning message when the level of theincorporated battery detected by at least one of said first batterylevel detector and said second battery level detector is lower than thepredetermined value.
 26. The music reproduction apparatus according toclaim 21, wherein said headphone comprises an electric field intensitydetector configured to detect an electric field intensity of an electricwave transmitted from said audio player and a warning section configuredto issue warning when the detected electric field intensity is lowerthan a predetermined value.
 27. The music reproduction apparatusaccording to claim 21, wherein said headphone comprises an error ratedetector configured to detect an error rate of an electric wavetransmitted from said audio player and a warning section configured toissue warning when the detected error rate is higher than apredetermined value.
 28. The music reproduction apparatus according toclaim 21, wherein said headphone comprises an electric field intensitydetector configured to detect an electric field intensity of an electricwave transmitted from said audio player, a first distance estimatorconfigured to estimate a first distance between said headphone and saidaudio player, an error rate detector configured to detect an error rateof the electric wave transmitted from said audio player, a seconddistance estimator configured to estimate a second distance between saidheadphone and said audio player, and a warning section configured toissue warning when at least one of the estimated first distance and theestimated second distance is longer than a predetermined distance.